STATEN ISLAND, N.Y. -- A raging fire deemed "suspicious" by a high-ranking FDNY official inflicted heavy damage on a 223-year-old home in Historic Richmond Town Wednesday evening -- just days before the historic district's signature event.

Two firefighters who suffered minor injuries were taken to Staten Island University Hospital, Prince's Bay.

The all-hands blaze was reported at the two-story Kruser-Finley House on Richmond Road, which dates to 1790, at 4:38 p.m., according to an FDNY spokeswoman.

Firefighters arrived within three minutes of the initial report and found both floors involved in fierce flames, said John Hodgens, deputy chief with the FDNY's Division 8. Hodgens deemed the fire suspicious and said its cause was under investigation.

A dozen units comprising 60 firefighters responded, and firefighters could be seen crawling across the roof as thick smoke billowed from the building.

Richmond resident Paul Tharp said that as he was negotiating "Snake Hill" in his car, "I get up close and see smoke swirling up from Richmond [Road]. I said, 'Omigod!'"

"The fire was going strong and the building started to shake, because it was an old tinderbox, it's like kindling, and the beautiful old wood, once it starts burning, it just goes."

Hodgens said the main fire was under control at 5:30 p.m. But at 5:42 p.m., he said, pockets of fire inside the roof sheathing erupted, leading to another effusion of smoke and flames before firefighters doused the renewed blaze with an exterior water stream.

"It was burning on the roof sheathing," said Hodgens. "Any house where the fire gets up into the roof area, you will have a deep-seated roof fire because it's layers, and the fire gets up into the layers."

It wasn't immediately clear whether the Kruser-Finley House could be salvaged, but gaping holes and the charred interior seemed to bode ill for its future. Between the flames and firefighters' efforts, the roof looked to be a total loss. "Unbelievable," said a shocked and dismayed Ed Wiseman, Richmond Town's executive director.

Wiseman said it was the first house fire he could recall in Historic Richmond Town. The only comparable event, he said, was a lightning strike on a bell tower in the 1980s.

According to Wiseman, the home was vacant and stored valuable items that were part of the Richmond Town collection. It was not open to the public.

Starting Saturday, Islanders will descend in droves on Richmond Town for the four-day Richmond County Fair. Wiseman vowed that the blaze wouldn't crimp the annual crowd-pleaser and fundraiser.

The director said officials have been working with the NYPD to beef up security. "We're constantly asking kids to leave after closing hours," he said. "But the area is not fenced in, so we can't [secure it] perfectly."

He urged anyone who may have seen something suspicious Wednesday to alert authorities.

The Kruser-Finely House sits behind a wooden fence near the intersection of Richmond and Arthur Kills roads.

"It does call attention to how much attention and care Historic Richmond Town needs," Wiseman said. "One fire extinguishes centuries of history."

Borough Historian Thomas Matteo lamented the destruction.

"It's horrible to think it was deliberate or suspicious, which makes it more tragic," said Matteo, lamenting young people's ignorance of their history and heritage.

Wiseman said that a few years ago, a historic structure report was done on the house with an eye toward renovation, akin to the $1 million work on nearby Britton Cottage.

Named for the two families with the longest periods of residence, the Kruser-Finley House -- which was relocated from Eltingville in 1965 -- is a clapboard residence with a fieldstone foundation and an unfinished basement. It comprises two sections, of which the newer, eastern part is lower in height and sided with shingles. Additions date to ca. 1820 and ca. 1850-60.

The house is an example of local vernacular residential construction of the 18th and early-19th centuries, according to reference texts.

It was designated an official landmark by the New York City Landmarks Preservation Commission in 1969. An exterior restoration was completed in 1980. ---Follow @siadvance on Twitter, join us on Facebook